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                ZCC Loves Intersection                </h1>
                <p>时间限制：1s&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;  空间限制：128MB</p>			</div>
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                                <h3>题目描述</h3><p><div>After beats all opponents in 3-dimension-world OI, ZCC feels bored and sets about going to other universes. In a universe with D dimension(s), ZCC finds D segments floating in the air. To be more precise: if we build a rectangular coordinate system with D axis, each of the segments is parallel with one axis, whose endpoints have a coordination of which all components belong to the set {x&isin;Z|0&le;x＜N}. For each axis, there is exactly one segment parallel with it.</div>
<div>Each of the D segments changes location every second. Read the pseudo code below for more details:</div>
<div><img src="../file/3841_0.jpg" width="555" height="290" alt="" /></div>
<div></div>
<div></div>
<div></div>
<div>Every second, from every pair of segments intersect, ZCC acquires a unit of Energy. Calculate the Expectation of the amount of the acquired energy per second please.</div>
<p></p></p><hr/><h3>输入格式</h3><p><div>There are several test cases in one input file. EOF indicates the end of input file.</div>
<div>Every test case contain two positive numbers N, D in one line.</div>
<div>It is guaranteed that 1＜N&le;10^9, D&le;99. The number of test cases&le;10.</div>
<p></p></p><hr/><h3>输出格式</h3><p><div>
<div>For each test case, output a line with an integer or an irreducible fraction p/q, which is the Expectation.</div>
</div>
<p></p></p><hr/><h3>样例输入</h3><pre>2 2
3 3
5 5</pre><hr/><h3>样例输出</h3><pre>1
49/81
18/625</pre><hr/><h3>提示</h3><p><div>For the first test case of the sample input, there are 2 segments in a 2*2 lattice.</div>
<div>Because two endpoint couldn&rsquo;t coincide, two segments must be (0,y)-(1,y) and (x,0)-(x,1). (x, y&isin;{0,1})&nbsp;</div>
<div>Thus, they always intersect at (x,y). As an irreducible fraction the answer is 1/1, where q = 1, so we should output an integer 1 instead.</div>
<div></div>
<p></p></p><hr/><h3>题目来源</h3><p>By 镇海中学</p>
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